Device for changing elongated objects

ABSTRACT

A device for successively changing elongated flexible sheets or similar flexible objects from an active position to non-active positions includes a drum, relative to which the sheets or similar flexible objects are fixed. The drum is rotatable in two opposing rotational directions. The rotational directions of the drum are controlled by a timing device in relation to the rotational speed of the motor so that rotation takes place in a first direction for such a time that the sheet located in the active position becomes wound up onto the drum and that a second sheet, located in the first rotational direction after the first sheet, is carried to a position from which the second sheet is unwound from the drum to the active position, upon rotation of the drum in the other rotational direction. Thereafter the drum is rotated in the other rotational direction for such a time that the second sheet becomes unwound from the drum. The rotation of the drum is subsequently stopped by the suitable timing device during such a time as is wanted in the active position for the second sheet. The timing procedure is repeated after the wanted time in the active position.

TECHNICAL FIELD

The present invention relates to a device for successively changingelongated flexible sheets or similar flexible objects from an activeposition to non-active positions. The device incorporates a drum,relative to which the sheets or similar flexible objects are fixed in asuitable manner. The said drum is rotatable by means of a motor.

BACKGROUND INFORMATION

Devices for changing posters or similar objects are known in a number ofmore or less complicated embodiments. The known devices are usually ofcomplicated design and many of them are also difficult and awkward withregard to changing posters for new ones. Apart from high complexityknown devices have the disadvantage that they are expensive to make.

Examples of such known devices are evident from, i.a., the Swedishpatent specification No. 7303560-2 and the U.S. Pat. No. 4,240,219.

OBJECT OF THE INVENTION AND SUMMARY

An object of the present invention is to provide a device for changingposters or similar elongated flexible objects which device is simple andinexpensive to manufacture and assemble, which has a simple and reliablefunction, with which it is easy for a layman to change posters etc: andwhich above all requires a minimum of maintenance and service.

The above tasks and objects have been solved in accordance with thepresent invention by means of the device mentioned in the descriptivepreamble in that the drum is rotatable in two opposing rotationaldirections, that the rotational directions of the drum are controlled bymeans of a suitable timing device in relation to the rotational speed ofthe motor so that rotation takes place in a first direction for such along time that the sheet located in the active position becomes wound uponto the drum and that a second sheet, located in the first rotationaldirection after the first sheet, is carried to a position from which thesecond sheet is unwound from the drum to the active positions uponrotation of the drum in the other rotational direction, and in that thedrum thereafter is rotated in the other rotational direction for such along time that the second sheet becomes unwound from the drum, and inthat the rotation of the drum is subsequently stopped by the suitabletiming device during such a long time as is wanted in the activeposition for the second sheet, and in that the aforesaid timingprocedure is repeated after the wanted time in the active position.

A particularly advantageous embodiment of the present invention is ifthe elongated flexible sheets or the similar flexible objects are fixed,either directly or indirectly, in relation to the preferably round drumat essentially the same mutual distances and if the number of used,elongated flexible sheets or similar flexible objects agree with thenumber of switching of the said motors rotational direction duringrotation of the drum one revolution.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in greater detail hereinbelow,with particular reference to an embodiment chosen by way of example andwith particular reference to the accompanying drawing, wherein:

FIG. 1 shows a perspective view of an embodiment chosen by way ofexample of the device according to the invention with posters or otherelongated objects removed;

FIG. 2 is an exploded view of the device according to FIG. 1 and withthe parts placed mutually separated and additionally redirected in somecases to clarify the same and;

FIG. 3 shows one part of the device according to FIG. 1 with postersapplied and;

FIG. 4 shows a variant of the setting as will become more apparentherein below.

DETAIL DESCRIPTION OF THE INVENTION

The device according to FIG. 1 incorporates a drum 5 with thereonapplied posters or similar elongated objects 1-4, see especially FIG. 3.The number of posters or similar can vary from two and upwards. In theexample shown in FIG. 3 four posters are used. The posters or similarelongated objects 1-4 are fixed in relation to the drum preferably atthe same mutual distances around the periphery of the drum, this beingachievable in several ways, for example a flexible carrier can befurnished with taped-on posters at a mutually fixed distance, the saidcarrier subsequently for example being taped or secured to the drum 5.Alternatively each posters can be fixed with tape relative to the drum.Obviously there are a large number of other possibilities for securingthe posters relative to the drum. For example the drum can be furnishedwith grooves in which folded over, relatively stiff ends of the posterscan be inserted and thereby fixed, or the posted can be clamped on bymeans of devices suitable for the purpose and not shown on the drawings.

The posters 1-4 are provided in the lower ends—if necessary—with weights2 a-4 a to stretch out the posters, see especially FIG. 3.

This drum 5 is rotated in its turn around its central axis in twoopposing rotational directions by means of a device suitable for thispurpose, preferably an electrically powered motor 6, see FIG. 2.Switching of the rotational direction for the motor 6 and thereby forthe drum 5 is governed by a time circuit which can consist either of anysuitable electric circuit available in the marketplace with suitablerelays, contactors, a computer control etc., or of a well attunedmechanical circuit which as a detailed example is described more closelyhereinbelow.

A description of changing of posters is made with reference to FIG. 3,where poster 1 is shown situated in the active position, for example inthe display position with an active displace of the poster 1 turned intowards the plane of the paper and/or located in the viewing direction,essentially covering behind located posters. Upon the said rotation ofthe drum 5 in the anti-clockwise direction all posters 1-4 or the likeare wound up simultaneously and together onto the drum 5. This rotationin the anti-clockwise direction takes place during such a long time thatall posters 1-4 have been wound up and that the next poster 4 in therotational direction of the drum and primarily its weight 4 a has passedover the uppermost point of the drum 5, which, however, the weight 3 aof the poster 3 following after poster 4 has not done. Thereafter therotational direction of the drum 5 is switched with the of the motor 6of the said time circuit, whereby the posted 4 is unwound completelyfrom the drum 5 to the active display position further in towards theplace of the paper which was previously occupied by poster 1. Obviouslythe ends of the posters 1-4 and their positions can be controlled bysome other means in order to control switching of rotational direction,whereof by way of example mention may be made of a light curtain or anelectric switch, which can react to passage of the rear edge of eachposter or its associated weight. By this means changing from poster 1 toposter 4 has taken place in the display position. The rotation of thedrum 5 is then caused with aid of the said time circuit to cease duringsuch a long time as it is desired to display the said poster 4 in theactive display position, whereafter the process above is repeated withrotation of the drum 5 in the anti-clockwise direction. Switching ofrotational direction takes place when poster 3 and primarily its weight3 a—or the rear edge of the poster, viewed in the rotationaldirection—but not weight 2 a—has passed over the uppermost point of thedrum 5, whereafter the rotational direction of the motor 6 of the saidtime circuit and thereby of the drum 5 is switched the process isrepeated, etc., etc.

As an example of an alternative to using a weight as above mention maybe made of a dolly roller which presses against the drum 5 and therebyagainst the wound posters.

In the text use is made of the expression posters and in the presentcontext this expression also relates to other times of elongatedflexible objects than posters, for example flexible felts, awnings,fabrics, carpets, wallpapers, roller blinds, rolling doors, sluices etc.

The drum 5 according to FIG. 2 is rotatably arranged relative to two endplates 18 and 19, located near the respective ends 5 b and 5 a of thedrum 5 and relative to a shaft 11 by means preferably of anappropriately electrically powered motor 6 attached to one end plate 19,the rotational direction of the said motor 6 being switchable by meansof an electric switch 17 which—via electrical wiring not shown in FIG. 2running from the switch 17 via the interior of a tube 21 to the motor6—reverses the rotational direction of the motor 6. The tube 21 fixesthe end plates 18 and 19 at a mutual distance which slightly exceeds theextent of the drum 5 in the same direction, enabling the drum 5 torotate freely between the end plates 18 and 19.

The shaft 11 is rotated by the outgoing shaft 6 a of the motor 6, whichis driven preferably via a threaded-on spring 22′, which evens outcertain unevenness in the running of the motor. This rotation of theshaft 11 takes place via first gearwheel 24, via two additionalgearwheels 23 and 25, a gear rim 26 and a ring 27 joined together withthe latter, and via a bearing bracket 20 for the shafts 23 a and 25 a ofgearwheels 23 and 25, in the centre 20 a of the said bearing bracket 20the shaft 11 is fixed. For supporting effect for bearing bracket 20there is proved a sleeve 28 pressed onto the ring 27 or formed with thelatter, which sleeve 28 is located on its outer surface close to theinside of the drum 5 and on its inner surface is located near thebearing bracket 20. It must nevertheless be emphasised that the drum 5runs freely in relation to the sleeve 28 and the latter canadvantageously be elaborated as a bearing surface. All the above drivingports for the shaft 11 are located inside the drum 5 and close to oneend 5 a of the drum. If so desired or needed the drive motor 6 forexample and other parts can be located inside the drum 5.

Close to the other end 5 b of the drum 5 on the rotating shaft 11 is afirst driver 12, fixed in the shaft 11 straight across the same, and anappropriate number of blocks 7-9 passed onto the shaft 11 and rotatablyarranged relative to the shaft 11, each of which blocks is provided withan associated, attached or integrated driver 7 a, 7 b; 8 a, 8 b; 9 a, 9b, which are placed at the same distance from the centre of the shaft11. The number of such blocks may be varied, depending on the timerequires in the active position or display position. A larger number ofsuch drives provides a possibility for a longer exposure time.

The distance which agrees essentially with the distance between thedriver 12 and a threaded portion 13 applied to the outer end of theshaft 11 corresponds largely to the distance between the blocks 7-9 sothat the first driver 12 on certain occasions interacts with driver 7 aon the block 7, driver 7 b interacts on certain occasions with driver 8a, driver 8 b interacts on certain occasions with driver 9 a, driver 9 binteracts on certain occasions with a further driver 10 a, which isapplied in a driver end plate 10 inserted into the other end 5 b of thedrum 5 and fixed in a suitably way at the same distance from the centreof the shaft 11 as the other drivers 7 a, 7 b, 8 a, 8 b, 9 a, 9 b. Thedriver end plate 10 is in this instance fixed relative to the drum 5. Itshould be noted here that the said driver end plate 10 has been shown inFIG. 2 slightly turned in relation to other parts in order for thefurther driver 10 a to be clearly apparent in the otherwise shown,mainly perspective view. The centre hole 10 b of the driver end plate 10affords a bearing surface for the shaft 11, whereby the drum 5 isrotatable relative to the shaft 11.

The shaft 11 continues through the end plate 18 with the threadedportion 13 of the shaft 11. Threaded onto this threaded portion 13 isfirst a nut 15 provided with a stop screw 15 a, the position of the saidnut thus being fixed relative to the threaded portion 13 of the shaft 11and then a nut 14 which in this instance is square. With a differentnumber of posters or similar than four, for example when using 3posters, the nut 14 is elaborated triangular, when using five postersthe nut is made five-sided, etc.

This angular nut 14 is arranged to lift in one position—determined bythe screw 15 provided with the stop nut 15 a—a lever 31 provided with astop 31 a, which lever in turn activates the electrical switch 17 or areverser not shown on the drawing to shift the rotational direction ofthe shaft 11. The switch 17 is fixed in the end plate 18 and the lever31 is movably located on a shaft 18 a, which also together with 18 b and18 c can comprise spacing means for a cover hood 29. The spacing means18 b and especially the portion located closet to the end plate 18 alsocomprises a fastener for one end of a spring 16, the other end of whichis secured in the lower part of the lever 31, whereby the lever 31 iscaused by the said spring 16 both to rotate around the shaft 18 a in itsupper part in the clockwise direction and also to tend to be moved inthe direction towards the end plate 18 along the shaft 18 a.

The shaft 11 rotates clockwise according to FIG. 2, whereupon thethreaded portion 13 rotates in the nut 14. This is prevented fromrotating in that its side bears against the inner surface of the lever31—parallel with the shaft 11. The nut 14 is moved outwards—from the endplate 18—until its outer side reaches a limiting wall 31 a on the lever31. By positioning the limiting wall 31 a at different axial distancesdifferent exposure times are obtained. When the nut 14 continues itsoutward movement the lever 31 is thereby caused to be moved outwards.Upon a certain movement the upper plane of the lever 31 leaves theoperating button of the switch 17, which button was previously pressedin on account of the influence of the lever 31 and the spring 16. Theoperating button of the switch 17, which is spring-loaded outwards, isnow permitted momentaneously to move outwards with the result that theshaft 11 now switches rotational direction and rotates anti-clockwise.

The nut 14 and the lever 31 are now moved inwards—due to the influenceof the spring 16—until the inner side of the upper part of the lever 31reaches the side of the operating button of the switch 17, whereupon thelever 31 discontinues its inward movement. The nut 14 continues itsinward movement until it reaches the nut 15 and is caused by the nut 15to rotate in the anti-clockwise direction. By this means the lever 31 isturned until its side edge 31 a passes the operating button of theswitch 17 and then especially past is surface which is located farthestaway from the switch 17. The spring 16 is now enabled to move the lever31 inwards past and over the operating button of the switch 17. The nut14 continues its anti-clockwise rotation. When the edge of the nut 14has passed the uppermost point of the lever 31—has turned through 90° inthis example where a square nut is used—the lever 31 is enabled on itssurface resting against the nut 14—due to the influence of the spring16—to rotate distinctly clockwise and press in the operating button ofthe switch 17 so that the shaft 11 assumes a reverse rotationaldirection and again rotates clockwise, whereupon the procedure isrepeated.

The parts in the shown embodiment which in the drawings are shown to belocated outside the drum 15 can—if necessary and if so wanted—be insteadlocated inside the said drum 5.

Illustrated in FIG. 4 is a somewhat different drum 5 with an associateddriver end plate 10. In this embodiment the end 5 b of the drum has beenprovided with a plurality of notches or grooves 5 b 1, 5 b 2, 5 b 3, 5 b4, etc. and the driver end plate 10 has been provided with a protrudingpin 10 c. Further a spring 10 d acts between the end plate 18 not shownin FIG. 4 and the driver end plate 10, pressing the latter against theend 5 b of the drum 5. By this means the pin 10 c is forced to interactWith one of the notches 5 b 1, 5 b 2, etc. The position of the driver 10a is changed by resetting this pin 10 c against the action of the spring10 d. Because of this the position of the nut 15 fitted with stop screw15 a is of less importance and an easily performed adjustment has beenaccomplished. The stop screw 15 a can even be dispensed with in such anembodiment. It should also be noted that the number of notches 5 b 1, 5b 2, etc. is not critical but on the other hand they should preferablycomprise slightly more than 90° when a square nut 14 is used, slightlymore than 120° when a triangular nut 14 is used, etc.

What is claimed is:
 1. A device for successively changing sheets (1-4)from an active position to non-active positions comprising a pluralityof elongated flexible sheets and a drum (5) operatively coupled to amotor and being rotatable by means of said motor (6), wherein said drum(5) is rotatable in two opposing rotational directions, the rotationaldirection of said drum (5) being controlled by a timing device having atiming procedure in relation to a rotational speed of the motor (6) sothat rotation takes place in a first direction for such a time that oneof said sheets (1) located in the active position becomes wound up ontothe drum and such that a second of said sheets (4) is carried to aposition from which said second sheet (4) is unwound from the drum (5)to the active position, upon rotation of said drum (5) in the otherrotational direction, and in that said drum (5) thereafter is rotated inthe other rotational direction for such a time that the second sheet (4)becomes unwound from the drum (5), and such that the rotation of thedrum (5) is subsequently stopped by the timing procedure during such atime as is wanted in the active position for the second sheet (4), andin that the timing procedure is repeated after the wanted time in theactive position.
 2. A device as claimed in claim 1, wherein said motoris an electrically powered motor (6), and wherein the timing devicecomprises an electric time control circuit with associated relays, andcontactors for control of said motor (6).
 3. A device as claimed inclaim 2, characterized in that the elongated flexible sheets (1-4) arefixed at least indirectly to the drum (5) at essentially the same mutualdistances.
 4. A device as claimed in claim 2, characterized in that theplurality of elongated flexible sheets (1-4) corresponds to a number ofreswitchings of the rotational directions of the said motor (6) duringrotation of the drum (5) through one revolution.
 5. A device as claimedin claim 2, characterized in that the said elongated flexible sheets(1-4) are mounted at a mutual distance on a carrier which in turn isarranged to be fixed in relation to the drum (5).
 6. A device as claimedin claim 2, characterized in that at least said timing device is locatedinside said drum (5).
 7. A device as claimed in claim 1, wherein saidmotor is an electrically powered motor (6), and wherein the timingdevice comprises a mechanically acting time control circuit whichcontrols the rotational direction of said motor (6).
 8. A device asclaimed in claim 7, characterized in that the elongated flexible sheets(1-4) are fixed at least indirectly to the drum (5) at essentially thesame mutual distances.
 9. A device as claimed in claim 7, characterizedin that the plurality of elongated flexible sheets (1-4) corresponds toa number of reswitchings of the rotational directions of the said motor(6) during rotation of the drum (5) through one revolution.
 10. A deviceas claimed in claim 7 characterized in that the said elongated flexiblesheets (1-4) are mounted at a mutual distance on a carrier which in turnis arranged to be fixed in relation to the drum (5).
 11. A device asclaimed in claim 7, characterized in that at least said timing device islocated inside said drum (5).
 12. A device as claimed in claim 7,wherein the mechanically acting time control circuit comprises amechanical circuit (7-10, 11-16) which controls the wanted time of thesaid active position and which is arranged to actuate an electric switch(17), which is arranged to change the rotational direction of the saidmotor (6).
 13. A device as claimed in claim 12, characterized in thatthe elongated flexible sheets (1-4) are fixed at least indirectly to thedrum (5) at essentially the same mutual distances.
 14. A device asclaimed in claim 12, characterized in that the plurality of elongatedflexible sheets (1-4) corresponds to a number of reswitchings of therotational directions of the said motor (6) during rotation of the drum(5) through one revolution.
 15. A device as claimed in claim 12characterized in that the said elongated flexible sheets (1-4) aremounted at a mutual distance on a carrier which in turn is arranged tobe fixed in relation to the drum (5).
 16. A device as claimed in claim12, characterized in that at least said timing device is located insidesaid drum (5).
 17. A device as claimed in claim 1, wherein the elongatedflexible sheets (1-4) are fixed, at least indirectly, to the drum (5) atessentially the same mutual distances.
 18. A device as claimed in claim1, wherein the plurality of elongated flexible sheets (1-4) coincideswith a number of reswitchings of the rotational directions of said motor(6) during rotation of the drum (5) through one revolution.
 19. A deviceas claimed in claim 1 wherein said elongated flexible sheets (1-4) aremounted at a mutual distance on a carrier which in turn is arranged tobe fixed in relation to the drum (5).
 20. A device as claimed in claim 1wherein at least said timing device is located inside said drum (5). 21.A device for successively changing sheets (1-4) from one active positionto non-active positions comprising a drum (5) operatively coupled to amotor and being rotatable by means of said motor (6), wherein said drum(5) is rotatable in two opposing rotational directions, the rotationaldirection of said drum (5) being controlled by a timing procedure inrelation to a rotational speed of the motor (6) so that rotation takesplace in a first direction for such a time that one of a plurality ofelongated flexible sheets (1) located in the active position becomeswound up onto the drum and such that a second of said plurality ofelongated flexible sheets (4) is carried to a position from which saidsecond sheet (4) is unwound from the drum (5) to the active position,upon rotation of said drum (5) in the other rotational direction, and inthat said drum (5) thereafter is rotated in the other rotationaldirection for such a time that the second sheet (4) becomes unwound fromthe drum (5), and such that the rotation of the drum (5) is subsequentlystopped by the timing procedure during such a time as is wanted in theactive position for the second sheet (4), and in that the timingprocedure is repeated after the wanted time in the active position.